"white" LED's vs. incandescent and halogen lights

"white" LED's vs. incandescent and halogen lights

Post by Autymn D. C » Tue, 15 Dec 2009 21:08:02


(strikes rec.bicycles.tech and sci.physics for sci.med.vision and
sci.optics)


Quote:

> > I've already sorted that. ?In conditions were road lighting could be
> > better and I need projection on the road, by current blue tint LED
> > mixes well with the available yellow sodium. ?Under better road
> > lighting then the blueness is more noticeable to other road users.
> > With no road lighting, the level of illumination is relatively poor
> > and is best supplemented with an incandescent of normal 2-3W levels.
> > it would be nice to see specifically what defects are and are not
> > shown up by the LED without risking riding unlit roads.at speed.

> The rods of the eye are most sensitive to blue light.

Wrong, blue (450 nm) is still dim no matter the hull--makes sense when
it's the retina's (redeye's) peak absorption a'owing to damp harmful
overblue liht, not to see any.  We can see loor (indigo to you, 420
nm) even better with our shortwave hull, and is proof blue is not a
firstly huered, and RGB anset is bunk.  All ye need to do is look at a
OD (optical disc)'s spectrum of sunliht to see it's RGL.

Anyhow, our rods are most afeel to blea-wert liht (498 nm for
scotopsin-11-cis-retinal hrodopsin), or shore- (where shore is 491 nm,
blea 470 nm--peak for bovine retinal eymelanin, wert 501 nm--in other
words emerald or sky+leaves).  It would help if ye and scientists
learn English first: http://google.com/groups?q=Einglish+Dohiwtsch.
But I warn thas the peak or median afeeldom and the mest or mean
afeeldom don't match when their plots are always skewed toward blues.
So blueshift all peaks to find their mest band, and blea-wert yields
blea--bingo, it's the sky, not the sea.

-Aut

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Autymn D. C » Tue, 15 Dec 2009 21:11:19


Quote:
> LEDs containing Arsen (galliumarsenide) will cause the
> NHS ? "Napoleon St. Helena Syndrome" by As-poisoning.

> Symptoms are: senility.

> Side note:
> Napoleon's green As-contaminated wallpapers were made
> by a German manufacturer. Justice at last.
> (Napoleon died of stomach cancer).

Any way you say thet, arse-poisoning or ass-poisoning, is freaken
funny.

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Autymn D. C » Tue, 15 Dec 2009 21:23:27


Quote:
> In article


> > The rods of the eye are most sensitive to blue light.

> 507 nm for rods, 555 nm for cones. ?Blue is 475 nm, green is 500 nm and
> yellow is 575 nm. ?Rods are most sensitive to green light.

> http://webvision.med.utah.edu/Facts.html

dissenty? {{cn}}

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Autymn D. C » Tue, 15 Dec 2009 21:28:13


Quote:
> (strikes rec.bicycles.tech and sci.physics for sci.med.vision and
> sci.optics)



> > > I've already sorted that. ?In conditions were road lighting could be
> > > better and I need projection on the road, by current blue tint LED
> > > mixes well with the available yellow sodium. ?Under better road
> > > lighting then the blueness is more noticeable to other road users.
> > > With no road lighting, the level of illumination is relatively poor
> > > and is best supplemented with an incandescent of normal 2-3W levels.
> > > it would be nice to see specifically what defects are and are not
> > > shown up by the LED without risking riding unlit roads.at speed.

> > The rods of the eye are most sensitive to blue light.

> Wrong, blue (450 nm) is still dim no matter the hull--makes sense when
> it's the retina's (redeye's) peak absorption a'owing to damp harmful
> overblue liht, not to see any. ?We can see loor (indigo to you, 420
> nm) even better with our shortwave hull, and is proof blue is not a
> firstly huered, and RGB anset is bunk. ?All ye need to do is look at a
> OD (optical disc)'s spectrum of sunliht to see it's RGL.

> Anyhow, our rods are most afeel to blea-wert liht (498 nm for
> scotopsin-11-cis-retinal hrodopsin), or shore- (where shore is 491 nm,
> blea 470 nm--peak for bovine retinal eymelanin, wert 501 nm--in other
> words emerald or sky+leaves). ?It would help if ye and scientists
> learn English first:http://google.com/groups?q=Einglish+Dohiwtsch.
> But I warn thas the peak or median afeeldom and the mest or mean
> afeeldom don't match when their plots are always skewed toward blues.
> So blueshift all peaks to find their mest band, and blea-wert yields
> blea--bingo, it's the sky, not the sea.

> -Aut


Quote:

> > In article


> > > The rods of the eye are most sensitive to blue light.

> > 507 nm for rods, 555 nm for cones.  Blue is 475 nm, green is 500 nm and
> > yellow is 575 nm.  Rods are most sensitive to green light.

> >http://webvision.med.utah.edu/Facts.html

> dissenty? {{cn}}

By the way, my spectrum was calibrate with plots thanks to Sam's laser
FAQ site.
 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Autymn D. C » Tue, 15 Dec 2009 21:29:25


Quote:
> (strikes rec.bicycles.tech and sci.physics for sci.med.vision and
> sci.optics)

oops, I mean sci.chem
 
 
 

"white" LED's vs. incandescent and halogen lights

Post by SMS » Wed, 16 Dec 2009 01:23:31

Quote:

>> And I pretty much agree with all the above.  But still, there are
>> (rare) times I wish my generator lights would give a _little_ more
>> light.

>> Which brings me to the question:  How soon before we can buy drop-in
>> replacement LED bulbs for existing bike headlight generator sets?

>> These things already exist for flashlights, for car taillights, and
>> for other applications for which the electrical problems are larger
>> (i.e. the need to regulate current by at least crude means).  Most
>> white LEDs will do fine with the regulated 1/2 amp that's naturally
>> produced by typical bike generators.

> All those are already DC.
> Cycle generators are AC.
> So your drop in replacement is going to need to rectify (and possibly
> smooth) the power.

That's the crux of the problem. Rectifying the AC to DC, filtering it,
and regulating the voltage or current, isn't difficult or expensive, but
  there's a big penalty in terms of efficiency, and you can't afford
those efficiency losses with a dynamo.

You can already buy LED modules that accept 8-15 VAC (built in
rectification) and operate over a wide range of voltages (built in
regulation). But building one that will work on the low current of a
typical bicycle dynamo, that's the hard part. Actually you could get by
with the 3W headlight, but that leaves nothing for the tail light unless
you get a 12V/6W tire driven dynamo, which costs $325.

It always comes back to the fact that to get adequate illumination with
a dynamo system you're looking at spending a _lot_ of money. It may be
worth it to a few people to eliminate the hassle of batteries, but the
reason dynamos are fading in popularity is that batteries are less of a
hassle than in the past.

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Clive Georg » Wed, 16 Dec 2009 01:40:55


Quote:
> That's the crux of the problem. Rectifying the AC to DC, filtering it, and
> regulating the voltage or current, isn't difficult or expensive, but
> there's a big penalty in terms of efficiency, and you can't afford those
> efficiency losses with a dynamo.

Care to quantify "big penalty"? Coz LED dynamo lights are out there, front
and rear, and are darned bright.
 
 
 

"white" LED's vs. incandescent and halogen lights

Post by thirty-si » Wed, 16 Dec 2009 02:19:46


Quote:


> > That's the crux of the problem. Rectifying the AC to DC, filtering it, and
> > regulating the voltage or current, isn't difficult or expensive, but
> > there's a big penalty in terms of efficiency, and you can't afford those
> > efficiency losses with a dynamo.

> Care to quantify "big penalty"? Coz LED dynamo lights are out there, front
> and rear, and are darned bright.

FA cup, sudden death on the penaty shoot out.
 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Frank Krygowsk » Wed, 16 Dec 2009 03:19:09


Quote:

> > Cycle generators are AC.
> > So your drop in replacement is going to need to rectify (and possibly
> > smooth) the power.

> That's the crux of the problem. Rectifying the AC to DC, filtering it,
> and regulating the voltage or current, isn't difficult or expensive, but
> ? there's a big penalty in terms of efficiency, and you can't afford
> those efficiency losses with a dynamo.

Wrong.

First, if you use two LEDs in anti-parallel, there is no rectifying
needed.  One conducts the positive half of the waveform and thus
protects the other from excessive reverse voltage; the other does the
same for the negative half of the waveform.

Second, regulation isn't needed with a typical bike generator.
They're naturally constant current devices, and the (essentially)
fixed half amp they produce is fine for most high-powered white LEDs.

That's how I visualized it, that's what happened when I bench tested
it, and that's what I was told by a friend of mine who's vice
president of engineering research for a firm that builds lighting
systems from high performance LEDs.

Third, if you choose to save money on the extra LED and just use a
full wave rectifier instead, your theoretical electrical efficiency
may be less; but the only efficiency that matters, which is road
illumination per unit of cyclist power input, is still better with the
LED & rectifier combination than it is with a halogen headlight.  And
generators powering halogen headlights have been used with perfect
success and great economy for many years by many thousands of
cyclists, despite the SMS claims of impossibility.

Quote:
> You can already buy LED modules that accept 8-15 VAC (built in
> rectification) and operate over a wide range of voltages (built in
> regulation). But building one that will work on the low current of a
> typical bicycle dynamo, that's the hard part.

It's obvious, then, that you've never tried.  Many others have done so
with home brews, and commercial ones are easily available.

Quote:
> Actually you could get by
> with the 3W headlight, but that leaves nothing for the tail light unless
> you get a 12V/6W tire driven dynamo, which costs $325.

Once again, you're wrong from an electrical standpoint.  And the price
you quote is more of your usual foolishness.  Using similar logic,
cranksets for bicycles are too expensive! Why? Because a Campy carbon
crank costs over $600.  Therefore, we should all scoot along with our
feet on the ground, Draisienne-style!

http://commons.wikimedia.org/wiki/File:Draisienne.jpg

- Frank Krygowski

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by AMuz » Wed, 16 Dec 2009 03:45:54

Quote:


>>> And I pretty much agree with all the above.  But still, there are
>>> (rare) times I wish my generator lights would give a _little_ more
>>> light.

>>> Which brings me to the question:  How soon before we can buy drop-in
>>> replacement LED bulbs for existing bike headlight generator sets?

>>> These things already exist for flashlights, for car taillights, and
>>> for other applications for which the electrical problems are larger
>>> (i.e. the need to regulate current by at least crude means).  Most
>>> white LEDs will do fine with the regulated 1/2 amp that's naturally
>>> produced by typical bike generators.

>> All those are already DC.
>> Cycle generators are AC.
>> So your drop in replacement is going to need to rectify (and possibly
>> smooth) the power.

> That's the crux of the problem. Rectifying the AC to DC, filtering it,
> and regulating the voltage or current, isn't difficult or expensive, but
>  there's a big penalty in terms of efficiency, and you can't afford
> those efficiency losses with a dynamo.

> You can already buy LED modules that accept 8-15 VAC (built in
> rectification) and operate over a wide range of voltages (built in
> regulation). But building one that will work on the low current of a
> typical bicycle dynamo, that's the hard part. Actually you could get by
> with the 3W headlight, but that leaves nothing for the tail light unless
> you get a 12V/6W tire driven dynamo, which costs $325.

> It always comes back to the fact that to get adequate illumination with
> a dynamo system you're looking at spending a _lot_ of money. It may be
> worth it to a few people to eliminate the hassle of batteries, but the
> reason dynamos are fading in popularity is that batteries are less of a
> hassle than in the past.

Huh. Define "a _lot_ of money".
The dynamo I rode this morning cost $9.95 in 1972. Plus a
few bulbs since.

--
Andrew Muzi
  <www.yellowjersey.org/>
  Open every day since 1 April, 1971

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by SMS » Wed, 16 Dec 2009 04:47:32

Quote:



>> That's the crux of the problem. Rectifying the AC to DC, filtering it, and
>> regulating the voltage or current, isn't difficult or expensive, but
>> there's a big penalty in terms of efficiency, and you can't afford those
>> efficiency losses with a dynamo.

> Care to quantify "big penalty"? Coz LED dynamo lights are out there, front
> and rear, and are darned bright.

Can you quantify "darned bright" first?
 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Clive Georg » Wed, 16 Dec 2009 04:49:25


Quote:



>>> That's the crux of the problem. Rectifying the AC to DC, filtering it,
>>> and regulating the voltage or current, isn't difficult or expensive, but
>>> there's a big penalty in terms of efficiency, and you can't afford those
>>> efficiency losses with a dynamo.

>> Care to quantify "big penalty"? Coz LED dynamo lights are out there,
>> front and rear, and are darned bright.

> Can you quantify "darned bright" first?

Stop ducking the question in the manner of a 5-year-old in a school
playground.

(but B+M can if you want).

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by SMS » Wed, 16 Dec 2009 04:51:02

Quote:

>> It always comes back to the fact that to get adequate illumination
>> with a dynamo system you're looking at spending a _lot_ of money. It
>> may be worth it to a few people to eliminate the hassle of batteries,
>> but the reason dynamos are fading in popularity is that batteries are
>> less of a hassle than in the past.

> Huh. Define "a _lot_ of money".
> The dynamo I rode this morning cost $9.95 in 1972. Plus a few bulbs since.

LOL, I was referring to the dynamos sold by Peter White, not the ones
sold by Yellow Jersey 37 years ago.

I do love your page at "http://www.yellowjersey.org/lolite.html". Too
bad you're out of the 12V/6W models. That was a good deal, even just for
the dynamo.    

 
 
 

"white" LED's vs. incandescent and halogen lights

Post by Just zis Guy, you know » Wed, 16 Dec 2009 04:55:34



Quote:
>It always comes back to the fact that to get adequate illumination with
>a dynamo system you're looking at spending a _lot_ of money. It may be
>worth it to a few people to eliminate the hassle of batteries, but the
>reason dynamos are fading in popularity is that batteries are less of a
>hassle than in the past.

well, I suppose that an unfounded assertion of "fading in popularity"
is progress from your previous unfounded assertion that dynamo
lighting cannot possibly be adequate.

Guy
--
http://www.chapmancentral.co.uk/urc
GPG public key at http://www.chapmancentral.co.uk/pgp-public-key.txt